From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751132AbWIZFti (ORCPT ); Tue, 26 Sep 2006 01:49:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751383AbWIZFtI (ORCPT ); Tue, 26 Sep 2006 01:49:08 -0400 Received: from cantor.suse.de ([195.135.220.2]:58081 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751339AbWIZFjR (ORCPT ); Tue, 26 Sep 2006 01:39:17 -0400 From: Greg KH To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Greg Kroah-Hartman Subject: [PATCH 23/47] PM: add /sys/power documentation to Documentation/ABI Date: Mon, 25 Sep 2006 22:37:43 -0700 Message-Id: <11592491581007-git-send-email-greg@kroah.com> X-Mailer: git-send-email 1.4.2.1 In-Reply-To: <11592491551919-git-send-email-greg@kroah.com> References: <20060926053728.GA8970@kroah.com> <1159249087369-git-send-email-greg@kroah.com> <11592490903867-git-send-email-greg@kroah.com> <11592490933346-git-send-email-greg@kroah.com> <1159249096460-git-send-email-greg@kroah.com> <11592490993970-git-send-email-greg@kroah.com> <11592491023995-git-send-email-greg@kroah.com> <1159249104512-git-send-email-greg@kroah.com> <11592491082990-git-send-email-greg@kroah.com> <1159249111668-git-send-email-greg@kroah.com> <11592491152668-git-send-email-greg@kroah.com> <115924911859-git-send-email-greg@kroah.com> <11592491211162-git-send-email-greg@kroah.com> <1159249124371-git-send-email-greg@kroah.com> <11592491274168-git-send-email-greg@kroah.com> <11592491303012-git-send-email-greg@kroah.com> <11592491342421-git-send-email-greg@kroah.com> <11592491371254-git-send-email-greg@kroah.com> <1159249140339-git-send-email-greg@kroah.com> <11592491451786-git-send-email-greg@kroah.com> <11592491482560-git-send-email-greg@kroah.com> <11592491512 235-git-send-email-greg@kroah.com> <11592491551919-git-send-email-greg@kroah.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki The file sysfs-power that documents the interface in the /sys/power/ directory is added to Documentation/ABI/testing. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-power | 88 +++++++++++++++++++++++++++++++++ 1 files changed, 88 insertions(+), 0 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power new file mode 100644 index 0000000..d882f80 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-power @@ -0,0 +1,88 @@ +What: /sys/power/ +Date: August 2006 +Contact: Rafael J. Wysocki +Description: + The /sys/power directory will contain files that will + provide a unified interface to the power management + subsystem. + +What: /sys/power/state +Date: August 2006 +Contact: Rafael J. Wysocki +Description: + The /sys/power/state file controls the system power state. + Reading from this file returns what states are supported, + which is hard-coded to 'standby' (Power-On Suspend), 'mem' + (Suspend-to-RAM), and 'disk' (Suspend-to-Disk). + + Writing to this file one of these strings causes the system to + transition into that state. Please see the file + Documentation/power/states.txt for a description of each of + these states. + +What: /sys/power/disk +Date: August 2006 +Contact: Rafael J. Wysocki +Description: + The /sys/power/disk file controls the operating mode of the + suspend-to-disk mechanism. Reading from this file returns + the name of the method by which the system will be put to + sleep on the next suspend. There are four methods supported: + 'firmware' - means that the memory image will be saved to disk + by some firmware, in which case we also assume that the + firmware will handle the system suspend. + 'platform' - the memory image will be saved by the kernel and + the system will be put to sleep by the platform driver (e.g. + ACPI or other PM registers). + 'shutdown' - the memory image will be saved by the kernel and + the system will be powered off. + 'reboot' - the memory image will be saved by the kernel and + the system will be rebooted. + + The suspend-to-disk method may be chosen by writing to this + file one of the accepted strings: + + 'firmware' + 'platform' + 'shutdown' + 'reboot' + + It will only change to 'firmware' or 'platform' if the system + supports that. + +What: /sys/power/image_size +Date: August 2006 +Contact: Rafael J. Wysocki +Description: + The /sys/power/image_size file controls the size of the image + created by the suspend-to-disk mechanism. It can be written a + string representing a non-negative integer that will be used + as an upper limit of the image size, in bytes. The kernel's + suspend-to-disk code will do its best to ensure the image size + will not exceed this number. However, if it turns out to be + impossible, the kernel will try to suspend anyway using the + smallest image possible. In particular, if "0" is written to + this file, the suspend image will be as small as possible. + + Reading from this file will display the current image size + limit, which is set to 500 MB by default. + +What: /sys/power/pm_trace +Date: August 2006 +Contact: Rafael J. Wysocki +Description: + The /sys/power/pm_trace file controls the code which saves the + last PM event point in the RTC across reboots, so that you can + debug a machine that just hangs during suspend (or more + commonly, during resume). Namely, the RTC is only used to save + the last PM event point if this file contains '1'. Initially + it contains '0' which may be changed to '1' by writing a + string representing a nonzero integer into it. + + To use this debugging feature you should attempt to suspend + the machine, then reboot it and run + + dmesg -s 1000000 | grep 'hash matches' + + CAUTION: Using it will cause your machine's real-time (CMOS) + clock to be set to a random invalid time after a resume. -- 1.4.2.1